1. Field of the Invention
The present invention relates to a solid state imaging system and more particularly to solid state imaging systems designed to obtain video color signals. The invention further relates to color filtering and electrical signal processing necessary to obtain a three color electrical video signal.
2. Description of the Prior Art
It has been proposed to use solid state imagers for color. A rather direct approach would be to use two or three imagers deriving an image from a common scene through separate filters. The cost of solid state imagers is sufficiently high, however, to reserve this approach for applications where the expense of an added imager is permissible. In low cost applications, it is desirable to use a single imager. Such a system has been proposed in U.S. Pat. No. 3,890,500 entitled "Apparatus for Sensing Radiation and Providing Electrical Readout" to Eichelberger et al, and assigned to the present Assignee. The color system there described employs a single imager using striped filters. Individual stripes are aligned with individual sensor columns in groups of two or three. In a three color system, for instance, a red pass, a green pass and a blue pass color filter stripe are arranged in repeating sequences of three. The imager is then addressed to the red lines in one field, the green lines in a second field, and the blue lines in a third field in repeated sequences to obtain a three color signal. The above approach is of somewhat lower resolution than optimum and is field sequential.